Topical delivery of antifungal agents

Superficial fungal infections of skin, hair, nails and the eye are among the most widespread diseases known to man. Topical therapy is the most favored form of treatment for these infections because it lends itself to self-administration, patient compliance, and absence of systemic adverse effects.

The clinical efficacy of antifungal drugs depends on the concentration achieved in cutaneous/ocular tissue, which in turn depends on the molecular mass, route of administration, duration of contact and ability of the compound to penetrate the tissue. Several of these agents have a high molecular mass > 500 Da (such as amphotericin B, natamycin, or ketoconazole), resulting in their poor penetration (even if they are lipophilic in nature). The latter causes relapse infections and requires frequent administration. Packaging these agents into suitable delivery systems can improve the effectiveness of these agents. The usefulness of liposomes/niosomes, lipid emulsions, nanoparticles including solid lipid nanoparticles and microemulsions for development of these agents is discussed.

This article aims to discuss limitations to the topical therapy of antifungal agents, and delivery approaches used to enhance their effectiveness.

A physicochemical and pharmacokinetic guided approach can help to tailor-make therapeutically effective systems for existing antifungal agents, thus doing away with the need for newer agents, which will save on time, money and manpower.